Membrane-Confined\nIron Oxychloride Nanocatalysts for\nHighly Efficient Heterogeneous Fenton Water Treatment

Abstract

Heterogeneous\nadvanced oxidation processes (AOPs) allow for the\ndestruction of aqueous organic pollutants via oxidation by hydroxyl\nradicals (^•OH). However, practical treatment scenarios\nsuffer from the low availability of short-lived ^•OH in aqueous bulk, due to both mass transfer limitations and quenching\nby water constituents, such as natural organic matter (NOM). Herein,\nwe overcome these challenges by loading iron oxychloride catalysts\nwithin the pores of a ceramic ultrafiltration membrane, resulting\nin an internal heterogeneous Fenton reaction that can degrade organics\nin complex water matrices with pH up to 6.2. With ^•OH confined inside the nanopores (∼ 20 nm), this membrane\nreactor completely removed various organic pollutants with water fluxes\nof up to 100 L m^–2 h^–1 (equivalent\nto a retention time of 10 s). This membrane, with a pore size that\nexcludes NOM (>300 kDa), selectively exposed smaller organics to ^•OH within the pores under confinement and showed excellent\nresiliency to representative water matrices (simulated surface water\nand sand filtration effluent samples). Moreover, the membrane exhibited\nsustained AOPs (>24 h) and could be regenerated for multiple cycles.\nOur results suggest the feasibility of exploiting ultrafiltration\nmembrane-based AOP platforms for organic pollutant degradation in\ncomplex water scenarios.